1. Field of the Invention
The present invention relates to an image calibrating, stitching and depth rebuilding method of a panoramic fish-eye camera and a system thereof, more particularly, to the image calibrating, stitching and depth rebuilding method of a panoramic fish-eye camera and a system thereof utilized for calibrating a panoramic image by means of an image stitching parameter (i.e. external calibration parameter) and a space depth transformation parameter acquired from a panoramic optical target space shot by a panoramic fish-eye camera, a depth calibration module for acquiring actual depth data between the camera and the target, and an internal calibration parameter of the panoramic fish-eye camera.
2. Description of the Prior Art
When the cameras are created in the world, people begin to record their daily life or important events in history by means of images. As to the technique and equipment of photography, low definition black and white pictures have been developed to high definition color pictures and to the high speed cameras which can shoot two billion frames per second in advance. Additionally, as to the visual effect of photography, not only the planar images but also the 3D images can be shot.
In the prior art, the 3D images are shot by utilizing a twin-lens camera of a 3D camera. But the 3D images can be shot within some angles of the view which are limited by the photographic scopes of the equipment, or the 360-degree surrounding panoramic images are shot by a photographer who holds a camera and turns around. However, the photographer must spend much time for shooting the panoramic images by utilizing this method. Therefore, a method for shooting a 3D panoramic image by utilizing several 3D cameras at the same time is provided
The configurations of three cameras to tens of cameras are existed now, but they all belong to the monocular vision system. And the depth information cannot be computed or acquired by utilizing parallax because of the photographic scopes overlapping of the camera. And the depth information is required for the 3D information of the virtual reality and the augmented reality. Consequently, how to get the 3D depth information by using the cameras is very important.
In order to solve the aforementioned problem, an image calibrating, stitching and depth rebuilding method of a panoramic fish-eye camera and a system thereof are provided. A panoramic image stitching parameter (external calibration parameter) is computed by means of finding out an internal calibration parameter between the semi-spherical shaped fish-eye lens and the planar CMOS sensor modules of the panoramic fish-eye camera and a panoramic optical target space shot by the panoramic fish-eye camera, and by means of building a space depth transformation parameter between a 2D planar image and an object depth in 3D space at the same time. Finally, the internal calibration parameter, the panoramic image stitching parameter (external calibration parameter) and the space depth transformation parameter are utilized to calibrate a panoramic image shot by the panoramic fish-eye camera for generating a 3D panoramic image.
However, another problem is generated in the aforementioned image calibrating, stitching and depth rebuilding method of a panoramic fish-eye camera and a system thereof. It is a heavy computing load for the computing hardware to compute the depth in the panoramic images of all targets in the panoramic optical target space shot by the panoramic fish-eye camera when a space depth transformation parameter is established. In addition, when the real images are shot, if one object of real scenes does not have any characteristic which can be recognized by the computer vision, the actual depth of the object will not be computed.
Therefore, the actual depth of some targets in the panoramic optical target space shall be acquired by the panoramic fish-eye camera first, and then the actual depth of some targets is utilized as a reference datum for computing the depth of other targets in the panoramic optical target space, so as to reduce the computing load of the computing hardware. And it becomes a new issue to be resolved.